Screw or nut driving device for portable power-driven rotary tools



May 6, 1930.

A. LEVEDAHL SCREW OR NUT DRIVING DEVICE FOR PORTABLE POWER DIVEN'ROTARY' rlOOLS Fiied sept. 2S, 1927 Patented May 6, 1930 UNITED STATES PATENT ori-Ica Am LEVEDAHL, l' LUBOBA, ILLINOIS, ABSIGNOB T0 INDEPENDENT mm1() TOOL OOEPANY, 0F CHICAGO, ILLINOIS, A GOBPOBLTION 0l' DELAWARE SCREW 0B NUT DRIVING DEVICE IOR PORTABLE POWER-DRIVER' ROTARY '1100138 Application med Septembere, 1987. Serial No. 881,608.

This invention relates to a screw or nut driving device for portable power driven rotary tools, such as drills, whereby screws and nuts may be set rapidly b power.

In my co ding app 'cation Serial No. 221,602, file September 23, 1927, I have disclosed and claimed a device for this purpose having three clutch members. These are-arranged in axial ali ent and increase the overall len h as w as the expense of makin the too e object of my present invention 1s to provide a device having only two clutch members, thereby shortening the length of the tool and consequently making it less expensive.

The invention consists further in the matterIsn hereinafter describexrnd claimed.

the accom an view through the hvice of my invention;

Fi 2 and 3 are transverse vertical section views taken on lines 2-2 and 3 3, respectively, of Fig. 1;

Fig. 4 is a longitudinal vertical sectional view through the tool holder, showing how a shank is inserted in or removed therefrom; and

Fig. 5 is an end view of the nut-engagin socket usable with said shank.

In Fig. 1, 1 indicates an extension of the tool casing at its forward end, and 2 indicates the rotary spindle of the tool journaled in said extension with a bearing bushing? between them. The spindle 2 1s driven y the high speedmotor of the tool through a reducing gear train (not shown which connects the spindle with the shaft o th motor. The spindle 2 projects beyond the forward end of the extension 1 and there has a clutch member 4 which is applied over the outer end of the spindle and held thereon by a key 5 and a set screw 6. f

The shaft 7 of the attachment is preferably made in one piece and extends forward of the spindle 2 and has its inner end portion 8 slidably and rotatably mounted in said spindle, the latter being made hollow, as at 9, so as to receive the end portion 8 of the shaft. A clutch member 10 is mounted on the shaft 7 beyond the clutch member 4. `A relatively clutch mem shoulder 12 prevents the clutch member 10 are apphed to the shaft.

hea vcoiled spring 11 is about the shaft forwar of the clutch member 10 and normally holds the same inst an annular shoulder 12 which is rovi rs 4 and 10, as shown; The

from slipping oi of the shaft in the direction of the tool proper.

The clutch member 10 is held from rotatinglwith respect to the shaft 7 rby three sets of ba keys 13, 13 located in registering grooves 14, 15 in the shaft 7 and clutch member 10, re-Y spectively, and `extending lengthwise thereof. The sets of keys and their grooves are spaced apart about the shaft lwith the grooves 14 in the shaft extending beyond the forward end of the clutch member 10 so that the balls may be inserted in the grooves before the sp 11 and its tension adjusting nut 16 When assembled, the 'nut 16 is close enough to the clutch member 10 to prevent the keys from working out of the grooves. The portion of the shaft 7 at the nut 16 is screw-threaded, as at 17, so that the nut may be adjusted endwisel of the shaft to adjust the tension of the spring 11 and thus determine the torque at which the clutch members will slip with respect to each other to disconnect the driving torque of the s indle 2 from the shaft 7 during the use o the tool. The nut 16` is locked in its positions of adjustment by a set-screw 18'carried by the nut,'a s shown.

ed on the shaft betweeny the f The clutch members 4 and 10 have co-oper; Y

ating clutch teeth or jaws 19, 20 on their o posed surfaces. These teeth are beyond t e outer periphery of theshoulder 12.so that they may engage for connecting the shaft 7 to the indle 2 on pressing the tool against the wor The teet or jaws 19, 20, have inclined side faces 21, 22 so that the teeth will Y slip and ratchet over eachother to disconmembers may be moved into complete en-.

gagement before the jaws take-hold to turn the shaft 7 by the spindle 2. This is especially advantageous in large size tools which are -heavy and require some little time to move' ythe inner en of the shaft 7 bears against the closed en d of the bore 9 in the spindle 2 and exerts a constant outward pressure on the shaft 7 tol force it outward from the spindle and move the'clutch members 4 and 10 apart to disconnect them on withdrawing the tool from the work, as well as normally holding members 4 and 10, as shown in said clutch members apart when the tool is not in use. To prevent the shaft 7 from working or dropplng out of the spindle '2, I

provide a guard 25 which may be in the form of a sleeve or cap secured to the extension 1 and extending over andhousin the clutch ig. 1. The cap or sleeve 25 has an inturned flange 26 at its outer end extending in front of the clutch member 10 and preventing it from leaving the sleeve. The opening in the flange 26 is large enough for the spring 11 to pass through and bear against the clutch member.

A tool holder 27 is securedV to the forward end of the shaft 7 beyond the nut-16 by a key 28. The holder 27 extends forward of the shaft 7 and there has a hexagonal socket 29 to receive the inner end of la similarly shaped shank 30 which may have at its outer end a blade 31 for driving screws, or a nut-engaging socket 32 for setting nuts. The manner in which the shank 30 is releasably retained in the socket 29 will be presently described.

The device operates as follows: The oper- .ator holding the tool engages the blade 31 in the ker'f of a screw or the socket 32 over a nut, depending on which is being driven, and then pushes the tool toward 'the screw or nut, thereby sliding the spindle' 2along the end portion 8 of the shaft 7 and causing the clutch member 4 to be moved into engagement with the clutch member 10. As thefspindle 2 has been l previously set 1in rotation --by turning on the motorfof the tool, the shaft 7. will be turned by the spindle to set the screw or nut as soon as'the clutch teeth'19, 20 take hold. They will remain engaged until the screw or nut becomes set to the desired tension, whereupon the resistance afforded by the tightened screw or nut to further turning will overcome the driving torque ofthe spindle on the shaft 7 throu h the clutch members and release the shaftg from the full driving torque of the spindle. With the clutch member 10 slidably mounted on the shaft 7, said clutch member will yield against its spring 11 and permit the teeth of the rotating clutch member 4 to slip and ratchet over those on the clutch member 10 and thus momentarily disengagethe clutch members as their teeth pass over each other. After the teeth have passed over one another they will again engage and kee up this action until the tool is allowed to go ack by the operator, when the clutch members will again assume their fully open or disengaged positions. As the teeth re-engage during the ratcheting action, repeated hammerlike blows are imparted to the shaft 7 and thus effect a'full tightening o f the screw or nut after it has been initially set. By adjustin the tension of the spring 1l', the time that t e shaft 7. becomes released from the driving tor ue of the spindle 2 may be deter mined and t us regulate the desired tension at which the screws or nuts are to be set. With the clutch-member 10 held by the spring 23 against the flange 2 6 of the guard when the clutch members are disengaged, the shaft4 7 will not rotate with the spindle 2 and thus may be grasped by the operator and be turned in anydirection to set the outer end of the shank 30 for proper engagement with the nut `or screw, as the case may be. Moreover,the

outer end of the shank will not mar the work when applied thereto as it is not in rotation at that time.

To releasably hold the shank 30 in the socket 29, the shank is provided adjacent its inner end with a surrounding groove 33. This groove is designed to receive the inner por' tions of a set of ball checks 34, 34, which arc carried by the holder 27 in suitable holes 35, 35. Slidably mounted over the outer end of the holder 27 is a sleeve 36 which has an interior flange 37 to force and holdthe ball checks 34 in the groove 33 of the shank when the latter'ha's been inserted to its full extent in the socket 29. A coiled spring 38 encircles the forward end of the holder 27 between the same and the sleeve 36 and bears against the flange 37 to normally hold it in a position over the ball checks 34, as shown in Fig. l, and thus lock the shank 30 in the socket. The outer end of this spring bears against a flange 39 at the outer end of the holder 27 and thus is prevented from slipping olf of the holder.

To release the shank from the socket, the i sleeve 36 is pulled forward compressing the 'spring and carrying the iange 37 forward of the ball checks 34. These are then free to be forced -outward into a recess 40 at the inner end of the sleeve by merely pulling the shank 30 out of the socket, as shown infFig. 4. On releasing the sleeve 36, the sprin returns it back to its normal position with tlie flange 37 over the ball checks and the latter are held with their lower ends pro'ecting into the socket 29. The inner ends o the holes 35 are extended slightly inward so as to yprevent the ball checks from droppingany further into the socket. 'On insertin a shank 30 into the socket,'the sleeve 36 is rst drawn forward `so asto release the flange 37 from the ball Ill vns

will move back into its normal checks, and the shank is fully in the socket, the lgroove33 is-in re 'ster with the lock the shank in the socket. This releasablel lock for the shank is quite simple'in construction and operation, is very effective, and moreovert provides a quick release of the shank and permits either a screw driving or a nut driving shank to be interchangeably used with the socketpler in construction than the threev clutch member arrangement as heretofore referred'.

to, and is shorter by the elimination of one of the clutch members. Consequently, the de' vice is less, expensive, as only two clutch mem# bers are required in place of three as in the other arrangement. While Athe device is shown in the form of an attachment for drill spindles, it may be made permanent therewith in tools which are desi ed especially for nut or screw driving. t e ball eys 13 reduce friction and permit easy sliding of the clutch member 10 on the shaft 7.

The details ofconstruction and arrangement of parts may be variously changed and modified without departing from the spirit and scope of my invention.

I claim as my invention:

l. In a portable ower driven rotary tool,

the combination with the rotary spindle of the tool, of a screw or nut driving shaft having its inner end slidably and rotatably mounted -insaid spindle, a pair of opposed jaw clutch members, one fixed on the spindle and the other slidable on the shaft for rotation therewith, spring means acting on the spindle and shaft for normally holding the clutch members disengaged, a shoulder on the shaft between the clutch members, and a s ring about the shaft and engaging the slida le clutch member thereon For normally holding the same against said shoulder.

2. In a portable power driven rotary tool, the combination with the rotary spindle of the tool, of a, screw or nut driving shaft having its inner end slidably and rotatably supported by the spindle, a pair of opposed jaw clutch members on thek spindle and shaft, respectively, and rotata le therewith, ball keys slidably connecting the clutch member on' the shaft with the same, spring means acting on the spindle and shaft for normally holding the clutch members; disengaged, a shoulder on the shaft between said clutch Vmembers, a s ring about the shaft and engaging the slida le clutch member thereon for normally holding the same against said shoulder, and a nut on the shaft for adjusting the ten-- sion of the spring.

3. In a portable power driven rotary tool, the combination with the rotary spindle of the tool, of a screw or nut driving device having a shaft having inner end slidably and rotatably mounted in said's indle, a pair of lopposed, annular jaw clutc members, one

fixed on the spindle and the other slidable onx the shaft but rotatable therewith spring means acting on the spindle and shaft for normally holding the c utch members disengaged, means permitting the slidable clutch member to yield to release the shaft from the driving torque of the spindle when the screw or nut becomes set, and means holding thev slidable clutch member from being rotated The device shown and described is simby the spindle whenthe clutch members are disengaged. v l

4. In a portable power driven rotary tool the combination with therotary spindle of thetool', of a screw or nut driving device vhaving a shaft havin its inner end slidably and shaft and spindle for normally hol ing the clutch members disengaged and at the same time pressing the clutch member on the shaft against said flange, and a spring about the .shaft beyond the sleeve for'engaging thel slidable clutch member and permitting it to yieldto release the shaft from the driving torque of the spindle when the screw or nut driven by said shaft becomes set.

5. In a portable wer driven rotary tool, the combination with the rotary spindle of the tool, of a screw or nut driving device having a shaft associated with said spindle, a pair of opposed annular jaw clutch members movable toward and from each other and constituting the driving andthe only clutch device between the shaft and thespindle; one clutch member being fixed on the spindle and the other clutch member being slidable on the shaft but rotatable therewith, and spring means permitting the slidable clutch member to yield to release the shaft from the driving torque of the spindle as soon as the screw or nut being driven by said shaft beber. on the shaft, sprlng means actin on the Y the combination with the rotary spindle of the tool, of a screw or nut driving device having a shaft slidably and rotatably supported i b the spindle, a pair of opposed annular jaw c -utch members mounted on the shaft and the spindle, respectively, for rotation therewith and constituting the driving and the only clutch device between the shaft and the' spindle, spring meansurging the shaft outward from bers o on pressing' the tool a ainst the work, -and means permitting one c utch member to yield with respect to the other clutch member to release the shaft from the full driving torgue of the spindle as soon as the screw or nut becomes set. Y

7. In a portable powerdriven rotary tool, the combination with the rotary spindle of the tool, of a screw or nut driving device having a. shaftslidably and rotatably supported by the spindle, a pair of opposed annular jaw clutch members on the shaft and the spindle, respectively, for rotation therewith and constituting the driving and the only clutch de# vice between theshaft and the spindle, spring means urging the shaft outward from the spindle to separate the clutch members on withdrawing the tool from the work but permitting the clutch members to engage on pressing the tool against thework, a sprin permitting one clutch member to yield w1 respect to the other clutch member to release the shaft from the full driving torque of the spindle as soon as the screw ornut becomes set, and means for adjusting the tension of saidspring. v

8. In a portable wer driven rotary tool, the combination with the rotary spindle of the tool, of a screw or nut driving device having a shaft slidably and rotably supported by the spindle, clutch members mounted on the shaft and the spindle, respectively, and constituting the driving and the only clutch device between the shaft and the spindle, one clutch member being fixed on the spindle and the other clutch member being slidably mounted on the shaft but rotatable therewith, spring means urging the shaft outward from the indle to separate the clutch members on wit drawing the tool from the work but permitting the clutch members to engage on pressing the tool against 'the work, and a coiled spring about the shaft on the outer side of the slidable clutch member to rpermit the latter to yield with respect to the other clutch member as soon as the screw or nut becomes set.

In testimony whereof I aix' my si ature.

AXEL LEVED .O

ae spindle toseparate the clutch memwithdrawin the tool from the workbut permitting the c utch members to engage a pair4 of opposed annular ]aw i 

